Protect excess heat heater contains (7)
I believe the answer is:
sheathe
'protect' is the definition.
Although both the answer and definition are verbs in their base form, I can't understand how one could define the other.
'excess heat heater contains' is the wordplay.
'contains' indicates a hidden word.
'SHEATHE' is hidden in the letters of 'excess heat heater'.
Can you help me to learn more?
(Other definitions for sheathe that I've seen before include "Put into scabbard" , "Put (a sword) it its cover" , "Protective cover, for sword say" , "Put (a sword) into its holder" , "Put (a sword) into case" .)